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Semester 5 November > Virology > Flashcards

Flashcards in Virology Deck (42)
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0
Q

Defn aseptic meningitis

A

Clinical/lab evidence of meningitis with neg bacterial culture

1
Q

Viral injury to CNS occurs by either

A

Cytolitic replication

Immunopathology

2
Q

Common causes of aseptic meningitis

A

Enteroviruses
Mumps

(RARE -HSV2)

3
Q

Histology of post infectious encephalomyelitis (ADEM)

A

Lymphocytic infiltrate

Peri vascular cuffing of adjacent blood vessels

4
Q

Lesions seen in ADEM

A

White matter lesions

NB molecular mimicry to myelin (T cell destroys)

5
Q

Cause of post infectious encephalomyelitis

A

Almost all viruses

Post vaccine

6
Q

Lesions seen in encephalitis

A

Grey matter lesions

7
Q

Signs in encephalitis

A
Fever
Drowsy
Decreased consciousness 
Focal signs
Confusion 
Convulsions
8
Q

Common causes of encephalitis

A

Herpes simplex
Rabies
Arboviridae

9
Q

Pathogenesis of acute flaccid paralysis

A

Enter via gut. Bloodstream. Cell bodies of motor neurons = grey matter lesions

10
Q

Spread of measles

A

Reap droplets

11
Q

Vaccine for measles

A

Live attenuated vaccine

Not earlier than 9 months = mother IgG prevents vaccine replication

12
Q

Who doesn’t get measles vaccine

A

Pregnant
Severely immunocomprimsed
(<1 year)

13
Q

Possible syndromes from measles in CNS

A

Acute Measles Post infectious encephalitis
Measles inclusion bodies (immunocomprimsed)
SSPE

14
Q

Spread of mumps

A

Resp droplets

15
Q

Distinguishing feature of mumps

A

Parotitis

16
Q

Period of aseptic meningitis in relation to parotitis in mumps

A

One week before to three weeks after

17
Q

What may follow aseptic meningitis in mumps

A

Encephalitis

18
Q

Vaccine for mumps

A

Live attenuated

Not in SA

19
Q

What is seen in 25% post pubertal men in mumps

A

Orchitis (may lead to infertility)

20
Q

How to diagnose mumps

A

Serology
Culture saliva/urine
PCR

21
Q

Is it useful to do PCR in post infectious encephalomyelitis

A

No. Immune reaction so no virus in CSF

22
Q

Spread of enteroviruses

A

Fecal oral

23
Q

What do enteroviruses most commonly cause in CNS

A

Aseptic meningitis

Acute flaccid paralysis

24
Q

Three clinical outcomes of polio

A

Asymptomatic
Minor febrile illness
Major illness - Acute flaccid paralysis
- aseptic meningitis
- respiratory paralysis

25
Q

Diagnosis of polio

A

PCR

Culture

26
Q

Vaccine for polio

A
Live attenuated oral (IgA)
Formalin Inactivated (IgG)
27
Q

Why six doses of polio virus vaccine

A

Only one strain ‘takes’ each time

28
Q

Four ways viruses can enter CNS

A

Anterograde neuronal transport
Retrograde neuronal transport (rabies, HSV)
Trojan horse by lymphocyte/ macs cell lines (west Nile, HIV)
Infection of endothelium in blood vessels in BBB

29
Q

Post exposure prophylaxis for rabies

A

Rabies Ab

Rabies vaccine

30
Q

Lethal syndrome that may develop after influenza

A

Reye’s syndrome
<18
Aspirin ingestion

31
Q

Pathogenesis of post infectious encephalomyelitis

A

Following viral infection, T cell confuse myelin in CNS with viral antigen epitope = molecular mimicry.
White cell lesions in CNS

32
Q

How does the immune system cause damage in viral infections?

A
  • cytotoxic T cells attack virus infected cells
  • antibody binding to infected cell attracts NK cells and triggers complement mediated cell lysis
  • antigen-antibody complexes cause inflammatory reactions
33
Q

Pathogenesis of post-infectious encephalomyelitis

A

T cells confuse the myelin in the brain with viral antigen epitope

34
Q

3 most common causes of uncomplicated viral meningitis

A
  • mumps
  • HSV
  • enteroviruses
35
Q

2 polio vaccines

A

OPV - live attenuated - at birth

IPV - killed - 6/10/14/18 weeks

36
Q

Post- exposure prophylaxis after dog bite

A
  • tetanus toxoid
  • wash with soap
  • antibodies into wound/deltoid
  • vaccine days 0,3,7,14
  • again on day 28 if immunocomp
37
Q

High risk HPV types

A
  • 16,18,31,33,35
38
Q

Virus causing progressive multifocal leukoenceohalopathy

A

JC virus

39
Q

Who is at risk of PML.

A

Immunocomp patients

40
Q

3 forms of measles in the CNS

A
  • acute measles post-infectious encephalitis (immunocompetent, AI,days to weeks, varied outcome)
  • measles inclusion body encephalitis (immunocomp, weeks to months, virus present, fatal)
  • subacute sclerosing panencephalitis (immunocompetent, years, slow progression to death)
41
Q

Difference between PIEM and GBS

A

GBS is demyelination of the peripheral nerves

PIEM is due to demyelination if the CNS